Splitting geometry of two models which are merged together
When you have one mesh object and you want parts of it to be hidden in object mode depending on some chosen options you can use a mask modifier.

To make use of the mask modifier you first setup some vertex groups, you may be able to do this by selecting based on the material applied, otherwise you need to select different vertices and add them to a group.

Once you have the vertex groups setup you can add a mask modifier for each group, then you can easily turn on/off the different parts.



The mask modifier shows only vertices in the selected group, clicking the arrows next to the vertex group name inverts this so it hides the chosen vertices.